SB95C - Sealing Internal Cable Transits

Hi,
The rear mech cable on the SB95C is routed through the rear triangle, but the holes where the cable enters and exits the triangle are not sealed. I am concerned about water and mud getting in through these unsealed holes and building up in the frame. Most other bike manufacturers seem to seal these transits. Has anyone found this to be a problem on their bike and/or come up with a method of sealing these holes?